[PATCH] D85597: [PGO] Delete dead comdat renaming code related to GlobalAlias. NFC

[Fangrui Song via Phabricator via llvm-commits]

MaskRay created this revision.
MaskRay added reviewers: davidxl, xur.
Herald added subscribers: llvm-commits, hiraditya.
Herald added a project: LLVM.
MaskRay requested review of this revision.

A GlobalAlias is an address-taken user of its aliased function.
canRenameComdatFunc has excluded such cases.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D85597

Files:
  llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
  llvm/test/Transforms/PGOProfile/comdat_rename.ll


Index: llvm/test/Transforms/PGOProfile/comdat_rename.ll
===================================================================
--- llvm/test/Transforms/PGOProfile/comdat_rename.ll
+++ llvm/test/Transforms/PGOProfile/comdat_rename.ll
@@ -10,6 +10,14 @@
   ret void
 }
 
+; Not rename Comdat with an alias (an alias is an address-taken user).
+$f_with_alias = comdat any
+; CHECK: $f_with_alias = comdat any
+define linkonce_odr void @f_with_alias() comdat {
+  ret void
+}
+ at f_alias = alias void (), void ()* @f_with_alias
+
 ; Not rename Comdat with right linkage.
 $nf = comdat any
 ; CHECK: $nf = comdat any
Index: llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
===================================================================
--- llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
+++ llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
@@ -693,7 +693,7 @@
     return false;
 
   // FIXME: Current only handle those Comdat groups that only containing one
-  // function and function aliases.
+  // function.
   // (1) For a Comdat group containing multiple functions, we need to have a
   // unique postfix based on the hashes for each function. There is a
   // non-trivial code refactoring to do this efficiently.
@@ -701,8 +701,7 @@
   // group including global vars.
   Comdat *C = F.getComdat();
   for (auto &&CM : make_range(ComdatMembers.equal_range(C))) {
-    if (dyn_cast<GlobalAlias>(CM.second))
-      continue;
+    assert(!isa<GlobalAlias>(CM.second));
     Function *FM = dyn_cast<Function>(CM.second);
     if (FM != &F)
       return false;
@@ -742,18 +741,8 @@
   NewComdat->setSelectionKind(OrigComdat->getSelectionKind());
 
   for (auto &&CM : make_range(ComdatMembers.equal_range(OrigComdat))) {
-    if (GlobalAlias *GA = dyn_cast<GlobalAlias>(CM.second)) {
-      // For aliases, change the name directly.
-      assert(dyn_cast<Function>(GA->getAliasee()->stripPointerCasts()) == &F);
-      std::string OrigGAName = GA->getName().str();
-      GA->setName(Twine(GA->getName() + "." + Twine(FunctionHash)));
-      GlobalAlias::create(GlobalValue::WeakAnyLinkage, OrigGAName, GA);
-      continue;
-    }
     // Must be a function.
-    Function *CF = dyn_cast<Function>(CM.second);
-    assert(CF);
-    CF->setComdat(NewComdat);
+    cast<Function>(CM.second)->setComdat(NewComdat);
   }
 }
 


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